In order to obtain genetic information for grain yield, seven genetically diverse wheat cultivars were crossed in an incomplete diallel to study the inheritance of grain yield using F_2 progenies for two years. Signif...In order to obtain genetic information for grain yield, seven genetically diverse wheat cultivars were crossed in an incomplete diallel to study the inheritance of grain yield using F_2 progenies for two years. Significant differences were observed among genotype, year and genotype × year interaction for grain yield, and both general combining ability(GCA) and specific combining ability(SCA) were also highly significant for grain yield, suggesting that the trait was controlled by both additive and non-additive effect. The GCA estimates revealed that the best combiners for grain yield were Yangmai 5 and Ningmai 9. Adequacy tests revealed that data of grain yield was fully adequate for genetic interpretation. Over-dominance genetic effects were important for the expression of grain yield. Grain yield exhibited moderately high value of narrow sense heritability(h_N^2=66.98% and h_N^2=72.37%).展开更多
[Objective]The study aimed to map QTLs(Quantitative trait loci)of heading stage for phtopeiod-thermo sensitive male sterile line BS366 in wheat.[Method] A population of 234 doubled haploid derived from the cross bet...[Objective]The study aimed to map QTLs(Quantitative trait loci)of heading stage for phtopeiod-thermo sensitive male sterile line BS366 in wheat.[Method] A population of 234 doubled haploid derived from the cross between BS366 and Baiyu149 was planted in Beijing and Funan in 2007,respectively.We used composite interval mapping(CIM)method to analyse the QTLs for heading stage.[Result]We detected 15 QTLs for heading stage.8 QTLs were detected in both Beijing and Funan,which were located on 1B,2A,2D,3B(2 loci),6B(2 loci)and 7B.A single QTL accounted for 2.42%-10.98% of pheotypic varience.[Conclusion] Eight QTLs which were detected under two environments could be applied for marker-assisted breeding and improvement of BS366.The QTL on chromosome 1B was new for heading stage,which enriches the QTL resource.展开更多
[Objective] The aim of this study was to determine the variation of phytic acid content (PAC) and its frequency distribution, as well as the relationship between PAC and protein content, kernel characteristics in 16...[Objective] The aim of this study was to determine the variation of phytic acid content (PAC) and its frequency distribution, as well as the relationship between PAC and protein content, kernel characteristics in 161 Chinese winter wheat cultivars from four regions. [Method] One hundred and sixty-one winter wheat varieties from China Wheat Zones I, II, III and IV (Table 1) were grown in a randomized block de- sign, in the 2009-2011 cropping season; and then the indexes for describing the grain morphological characteristics such as the thousand kernel weight (TKW), kernel length (KL), kernel width (KW) and kernel thickness (KT) were measured; the phytic acid content (PAC), protein content and sedimentation value were also determined; finally, the relationship between PAC and protein content, kernel characteristics were analyzed. [Result] The PAC in the cultivars tested ranged from 0.92% to 1.95% with a mean value of 1.41%. Protein content ranged from 12.60% to 19.20%, with a mean of 15.24%. Most (53.4%) of the wheat genotypes had a PAC value in the range of 1.25% to 1.55%. No significant correlation was found between PAC and protein content, sedimentation value, while protein content and SDS sedimentation value was significant correlated, which suggested the possibility of breeding wheat cultivars that have a low PAC but a high protein content and good gluten quality. There was a high correlation between TKW and KW (,.=0.79), KL (r=0.50) and KT (r=0.64). PAC was found having no significant correlation with TKW, KW, KL and KT. [Conclusion] The result suggests the possibility of breeding wheat cultivars that have a low PAC but high kernel weight.展开更多
Quantitative trait loci (QTLs) for plant height in wheat (Triticum aestivum L.) were studied using a set of 168 doubled haploid (DH) lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage ...Quantitative trait loci (QTLs) for plant height in wheat (Triticum aestivum L.) were studied using a set of 168 doubled haploid (DH) lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage map was constructed using 283 SSR and 22 EST-SSR markers. The DH population and the parents were evaluated for wheat plant height in 2005 and 2006 in Tai'an and 2006 in Suzhou. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. Four additive QTLs and five pairs of epistatic effects were detected, which were distributed on chromosomes 3A, 4B, 4D, 5A, 6A, 7B, and 7D. Among them, three additive QTLs and three pairs of epistatic QTLs showed QTL×environment interactions (QEs). Two major QTLs, Qph4B and Qph4D, which accounted for 14.51% and 20.22% of the phenotypic variation, were located similar to the reported locations of the dwarfing genes Rhtl and Rht2, respectively. The Qph3A-2 with additive effect was not reported in previous linkage mapping studies. The total QTL effects detected for the plant height explained 85.04% of the phenotypic variation, with additive effects 46.07%, epistatic effects 19.89%, and QEs 19.09%. The results showed that both additive effects and epistatic effects were important genetic bases of wheat plant height, which were subjected to environmental modifications, and caused dramatic changes in phenotypic effects. The information obtained in this study will be useful for manipulating the QTLs for wheat plant height by molecular marker-assisted selection (MAS).展开更多
The effects of osmotic stress on the ATPase activity, the contents of —SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [Triticum aestivum L. cv. Yumai No.18(drought-tolerant) and cv. ...The effects of osmotic stress on the ATPase activity, the contents of —SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [Triticum aestivum L. cv. Yumai No.18(drought-tolerant) and cv. Yumai No.9(drought-sensitive)] roots were investigated. The results showed that ATPase activity and —SH group content decreased with polyethylene glycol(PEG) 6000(-0.55 MPa) treatment for 7 d, in concert with the decrease of the ratio of noncovalently conjugated spermidine(NCC-Spd)/noncovalently conjugated putrescine(NCC-Put) and increase of the covalently conjugated putrescine(CC-Put). Osmotic stress injury to Yangmai No.9 seedlings was alleviated greatly with 1 mmol/L exogenous spermidine(Spd), in concert with marked increases of the ratio of NCC-Spd/NCC-Put, —SH group contents and ATPase activity in mitochondrial membrane. Under osmotic stress, the concomitant treatment of Yumai No.18 seedlings with methylglyoxyl bis(guanylhydrazone) (MGBG), an inhibitor of S-adenosyl methionine decarboxylase(SAMDC), and phenanthrolin (o-Phen), an inhibitor of transglutaminase(TGase), caused a significant decrease of the ratio of NCC-Spd / NCC-Put, CC-Put contents, respectively, in concert with the marked decreases of ATPase activity, —SH group content and its tolerance to osmotic stress. All the results above suggested that osmotic stress tolerance of wheat seedlings was associated with the ATPase activity, the contents of —SH group, NCC-Spd and CC-Put in mitochondrial membrane.展开更多
Drought is a major constraint in many wheat( Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in...Drought is a major constraint in many wheat( Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in a double haploid (DH) population derived from the cross, Hanxuan10×Lumai14, using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Interval mapping analysis revealed that QTLs for drought tolerance at germination stage were located on chromosomes 1B, 2B, 5A, 6B, 7A and 7B, respectively, and the most effective QTL was mapped on chromosome 2B, explaining 27.2% of phenotypic variance. The QTLs for drought tolerance at seedling stage were located on 1B, 3B and 7B, respectively, and the most effective QTL was mapped on chromosome 3B, explaining 21.6% of phenotypic variance. Their positions were different from those of QTLs conferring drought tolerance at germination stage, indicating that drought tolerance at germination stage and seedling stage was controlled by different loci. Most of the identified QTLs explained 18% or more of phenotypic variance for drought tolerance at germination and seedling stage, and would be useful in future for marker assisted selection programs and cultivar improvement.展开更多
Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and the functionality of wheat products. Two high-yield winter wheat cultivars were used to evaluate th...Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and the functionality of wheat products. Two high-yield winter wheat cultivars were used to evaluate the effects of the application of exogenous ABA or GA during the reproductive phase of the initial grain filling on starch granule size distribution and starch components in grains at maturity. The results indicated that a bimodal curve was found in the volume and surface area distribution of grain starch granules, and a unimodal curve was observed for the number distribution under all treatments. The exogenous ABA resulted in a significant increase in the proportions (both by volume and by surface area) of B-type (〈9.9 Ixm in diameter) starch granules, with a reduction in those of A-type (〉9.9 ~tm) starch granules, while, the exogenous GA3 led to converse effects on size distribution of those starch granules. The exogenous ABA also increased starch, amylose and amylopectin contents at maturity but significantly reduced the ratio of amylose to amylopectin. Application of GA3 significantly reduced starch content, amylopectin content but increased the ratio of amylose to amylopectin. The ratio of amylose to amylopectin showed a significant and negative relationship with the volume proportion of granules 〈9.9 μm, but was positively related to the volume proportion of granules 22.8-42.8 μm.展开更多
Wheat leaf rust,caused by Puccinia triticina(Pt),is an important foliar disease that has an important influence on wheat yield.The most economic,safe and effective way to control the disease is growing resistant culti...Wheat leaf rust,caused by Puccinia triticina(Pt),is an important foliar disease that has an important influence on wheat yield.The most economic,safe and effective way to control the disease is growing resistant cultivars.In the present study,a total of 46 wheat landraces and 34 wheat lines with known Lr(leaf rust resistance)genes were inoculated with 16Pt pathotypes for postulating seedling resistance gene(s)in the greenhouse.These cultivars and five wheat differential lines with adult plant resistance(APR)genes(Lr12,Lr22b,Lr34,Lr35 and Lr37)were also evaluated for identification of slow rusting resistance in the field trials in Baoding,Hebei Province of China in the 2014–2015 and 2015–2016 cropping seasons.Furthermore,10 functional molecular markers closely linked to 10 known Lr genes were used to detect all the wheat genotypes.Results showed that most of the landraces were susceptible to most of the Pt pathotypes at seedling stage.Nonetheless,Lr1 was detected only in Hongtangliangmai.The field experimental test of the two environments showed that 38 landraces showed slow rusting resistance.Seven cultivars possessed Lr34 but none of the landraces contained Lr37 and Lr46.Lr genes namely,Lr9,Lr19,Lr24,Lr28,Lr29,Lr47,Lr51 and Lr53 were effective at the whole plant stage.Lr18,Lr36 and Lr45 had lost resistance to part of pathotypes at the seedling stage but showed high resistance at the adult plant stage.Lr34 as a slowing rusting gene showed good resistance in the field.Four race-specific APR genes Lr12,Lr13,Lr35 and Lr37 conferred good resistance in the field experiments.Seven race-specific genes,Lr2b,Lr2c,Lr11,Lr16,Lr26,Lr33 and LrB had lost resistance.The 38 landraces showed slow rusting resistance to wheat leaf rust can be used as resistance resources for wheat resistance breeding in China.展开更多
Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and functionality. Two types of wheat cultivars, the hard and soft wheat cultivars, grown at Tai'an Ex...Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and functionality. Two types of wheat cultivars, the hard and soft wheat cultivars, grown at Tai'an Experimental Station of Shandong Agricultural University, Taian, Shandong, China, were examined in this study. The granule size distribution and amylose contents in wheat grains were studied and compared, and relationships between the properties were identified. A clear bimodal distribution of granule size was shown in all wheat cultivars. Volume distribution of starch granules shows the typical bimodal with peak values in the ranges of 5.6-6.1μm and 20.7-24.9μm, respectively. Also, granule surface area distribution was bimodal with peak values in the ranges of 2.4-3.2μm and 20.7-24.9μm, respectively. Number distribution of granules was a typical population with a peak value in the range of 0.54-1.05μm. Contributions from the granules 〈 2.8μm and 〈 9.9μm to the total volume were in the ranges of 94.2-95.1% and 99.7-99.9% of total number, respectively. Proportions of granules〈2.8μm, 2.8-9.9μm, 9.9-22.8μm, and 22.8-42.8μm were in the ranges of 12.9-14.3%, 28.4-31.1%, 33.5-35.6%, and 19.7-22.7% for hard wheat, and 10.3-13.9%, 26.6-28.1%, 32.7-34.6%, and 24.2-27% for soft wheat. Hard wheat had greater B-type granules ( 〈 9.9μm), and had fewer granules of 22.8-42.8μm than soft wheat. Amylose content was positively related to volume percentage of granules 22.8-42.8μm, and negatively related to volume percentage of granules 2.8-22.8μm.展开更多
The quality or structure of a wheat population is significantly affected by the compositions of tillers. Little has been known about the physiological basis for the differences of productive capacity among tillers. Tw...The quality or structure of a wheat population is significantly affected by the compositions of tillers. Little has been known about the physiological basis for the differences of productive capacity among tillers. Two winter wheat cultivars, Shannong 15(SN15) and Shannong 8355(SN8355), were used to investigate the differences of productive capacity among tillers and analyze the physiological mechanisms that determine the superior tiller group. Low-position tillers(early initiated tillers) had a higher yield per spike than high-position tillers(late initiated tillers) in both cultivars, which was due to their more grain number per spike, more fertile spikelet per spike, less sterile spikelet per spike and higher grain weight. According to cluster analysis, tillers of SN15 were classified into 2 groups: superior tiller group including main stem(0), the first primary tiller(I) and the second primary tiller(II); and inferior tiller group including the third primary tiller(III) and the first secondary tiller(I-p). Tillers of SN8355 were classified into 3 groups: superior tiller group(0 and I), intermediate tiller group(II and III) and inferior tiller group(I-p). In comparison with other tiller groups, the superior tiller group had higher photosynthetic rate of flag leaves, higher antioxidant enzyme(SOD, POD and CAT) activities and lower levels of lipid peroxidation in leaves, higher grain filling rate in both superior and inferior grains during grain filling, higher single-stem biological yield and larger single-stem economic coefficient. Correlation analysis showed that yield per spike was positively and significantly correlated with the flag leaf photosynthetic rate, grain filling rate, the antioxidant enzyme activities and soluble protein content(except for SN15 at 5 days post-anthesis(DPA)) of flag leaf, the single-stem biological yield, and the single-stem economic coefficient. Remarkable negative correlation was also found between yield per spike and MDA content of flag leaf. These results suggested that superior tiller group had stronger leaf photosynthetic capacity, more predominance in terms of grain filling, slower senescence rate, higher biological yield and larger economic coefficient, and therefore, showed greater productive capacity than other tiller groups.展开更多
Soil management practices affect rhizosphere microorganisms and enzyme activities, which in turn influence soil ecosystem processes. The objective of this study was to explore the effects of different nitrogen applica...Soil management practices affect rhizosphere microorganisms and enzyme activities, which in turn influence soil ecosystem processes. The objective of this study was to explore the effects of different nitrogen application rates on wheat(Triticum aestivum L.) rhizosphere soil microorganisms and enzyme activities, and their temporal variations in relation to soil fertility under supplemental irrigation conditions in a fluvo-aquic region. For this, we established a split-plot experiment for two consecutive years(2014–2015 and 2015–2016) in the field with three levels of soil moisture: water deficit to no irrigation(W1), medium irrigation to(70±5)% of soil relative moisture after jointing stage(W2), and adequate irrigation to(80±5)% of soil relative moisture after jointing stage(W3);and three levels of nitrogen: 0 kg ha^–1(N1), 195 kg ha^–1(N2) and 270 kg ha^–1(N3). Results showed that irrigation and nitrogen application significantly increased rhizosphere microorganisms and enzyme activities. Soil microbiological properties showed different trends in response to N level;the highest values of bacteria, protease, catalase and phosphatase appeared in N2, while the highest levels of actinobacteria, fungi and urease were observed in N3. In addition, these items performed best under medium irrigation(W2) relative to W1 and W3;particularly the maximum microorganism(bacteria, actinobacteria and fungi) amounts appeared at W2, 5.37×10^7 and 6.35×10^7 CFUs g^–1 higher than those at W3 in 2014–2015 and 2015–2016, respectively;and these changes were similar in both growing seasons. Microbe-related parameters fluctuated over time but their seasonality did not hamper the irrigation and fertilization-induced effects. Further, the highest grain yields of 13 309.2 and 12 885.7 kg ha^–1 were both obtained at W2 N2 in 2014–2015 and 2015–2016, respectively. The selected properties, soil microorganisms and enzymes, were significantly correlated with wheat yield and proved to be valuable indicators of soil quality. These results clearly demonstrated that the combined treatment(W2 N2) significantly improved soil microbiological properties, soil fertility and wheat yield on the Huanghuai Plain, China.展开更多
Through regulating target genes via the mechanisms of posttranscriptional cleavage or translational repression, plant miRNAs involve diverse biological processes associating with plant growth, development, and abiotic...Through regulating target genes via the mechanisms of posttranscriptional cleavage or translational repression, plant miRNAs involve diverse biological processes associating with plant growth, development, and abiotic stress responses, in this study, we functionally characterized TaMIR1119, a miRNA family member of wheat (Triticum aestivum), in regulating the drought adaptive response of plants. TaMIR1119 putatively targets six genes categorized into the functional classes of transcriptional regulation, RNA and biochemical metabolism, trafficking, and oxidative stress defense. Upon simulated drought stress, the TaMIR1119 transcripts abundance in roots was drastically altered, showing to be upregulated gradually within a 48-h drought regime andthat the drought-induced transcripts were gradually restored along with a 48-h recovery treatment. In contrast, most miRNA target genes displayed reverse expression patterns to TaMIR1119, exhibiting a downregulated expression pattern upon drought and whose reduced transcripts were re-elevated along with a normal recovery treatment. These expression analysis results indicated that TaMIR1119 responds to drought and regulates the target genes mainly through a cleavage mechanism. Under drought stress, the tobacco lines with TaMIR1119 overexpression behaved improved phenotypes,, showing increased plant biomass, photosynthetic parameters, osmolyte accumulation, and enhanced antioxidant enzyme (AE) activities relative to wild type. Three AE genes, NtFeSOD, NtCAT1;3, and NtSOD2,1, encoding superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) proteins, respectively, showed upregulated expression in TaMIR1119 overexpression lines, suggesting that they are involved in the regulation of AE activities and contribution to the improved cellular reactive oxygen species (ROS) homeostasis in drought-challenged transgenic lines. Our results indicate that TaMIR1119 plays critical roles in regulating plant drought tolerance through transcriptionally regulating the target genes that modulate osmolyte accumulation, photosynthetic function, and improve cellular ROS homeostasis of plants.展开更多
To evaluate the possible genetic interrelationships between flour components and the sedimentation volume(SD),a doubled haploid(DH) population comprising 168 lines were used to identify the conditional quantitativ...To evaluate the possible genetic interrelationships between flour components and the sedimentation volume(SD),a doubled haploid(DH) population comprising 168 lines were used to identify the conditional quantitative trait loci(QTLs) for SD in three environments.Ten additive QTLs and 15 pairs of epistatic QTLs were detected for SD through unconditional and conditional QTL mapping.Three major additive QTLs were detected for SD conditioned on the seven quality traits.Two additive QTLs were found to be independent of these traits.Three additive QTLs were suppressed by three of the seven traits because of non-detection in unconditional mapping.Three pairs of epistatic QTLs were completely affected by the seven traits because of detection in unconditional mapping but no-detection in conditional mapping.Twelve pairs of epistatic QTLs were detected in conditional mapping.Our results indicated that conditional mapping could contribute to a better understanding of the interdependence of different and closely correlated traits at the QTL molecular level,especially some minor QTLs were found.The conditional mapping approach provides new insights that will make it possible to avoid the disadvantages of different traits by breeding through molecular design.展开更多
The relationship between vernalization requirement and quantitative and qualitative changes in total leaf soluble proteins were determined in one spring (cv. Kohdasht) and two winter (cvs. Sardari and Norstar) cul...The relationship between vernalization requirement and quantitative and qualitative changes in total leaf soluble proteins were determined in one spring (cv. Kohdasht) and two winter (cvs. Sardari and Norstar) cultivars of wheat (Triticum aestivum L.) exposed to 4℃. Plants were sampled on days 2, 14, 21 and 35 of exposure to 4℃. The final leaf number (FLN) was determined throughout the vernalization periods (0, 7, 14, 24, and 35 d) at 4℃. The final leaf number decreased until days 24 and 35 in Sardari and Norstar eultivars, respectively, indicating the vernalization saturation at these times. No clear changes were detected in the final leaf number of Kohdash cultivar, verifying no vernalization requirement for this spring wheat cultivar. Comparing with control, clear cold-induced 2-fold increases in proteins quantity occurred after 48 h following the 4℃-treatment in the leaves of the both winter wheat cultivars but, such response was not detected in the spring cultivar. However, the electrophoretic protein patterns showed between-cultivar and between-temperature treatment differences. With increasing exposure time to 4℃, the winter cultivars tended to produce more HMW polypeptides than the spring cultivar. Similar proteins were induced in both Sardari and Norstar winter wheat cultivars, however, the long vernalization requirement in Norstar resulted in high level and longer duration of expression of cold-induced proteins compared to Sardari with a short vernalization requirement. These observations indicate that vernalization response regulates the expression of low temperature (LT) tolerance proteins and determines the duration of expression of LT- induced proteins.展开更多
In this study, 14 wheat cultivars with contrasting yield and N use efficiency (NUE) were used to investigate the agronomic and NUE-related traits, and the N assimilation-associated enzyme activities under low and hi...In this study, 14 wheat cultivars with contrasting yield and N use efficiency (NUE) were used to investigate the agronomic and NUE-related traits, and the N assimilation-associated enzyme activities under low and high N conditions. Under deficient-N, the cultivars with high N uptake efficiency (UpE) and high N utilization efficiency (UtE) exhibited higher plant biomass, yields, and N contents than those with medium and low NUEs. The high UpE cultivars accumulated more N than other NUE type cultivars. Under sufficient-N, the tested cultivars showed similar patterns in biomass, yield, and N content to those under deficient-N, but the varietal variations in above traits were smaller. In addition, the high UpE cultivars displayed much more of root biomass and larger of root length, surface area, and volume than other NUE type cultivars, indicating that the root morphological traits under N deprivation are closely associated with the plant biomass through its improvement of the N acquisition. The high UtE cultivars showed higher activities of nitrate reductase (NR), nitrite reductase (NIR), and gluta- mine synthetase (GS) at stages of seediling, heading and filling than other NUE type cultivars under both low and high N conditions. Moreover, the high UpE and UtE cultivars also displayed higher photosynthetic rate under deficient-N than the medium and low NUE cultivars. Together, our results indicated that the tested wheat cultivars possess dramatically genetic variations in biomass, yield, and NUE. The root morphological traits and the N assimilation enzymatic acitivities play critical roles in regulating N accumulation and internal N translocation under the N-starvation stress, respectively. They can be used as morphological and biochemical references for evaluation of UpE and UtE in wheat.展开更多
Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers...Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yandal817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157, Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.展开更多
Wheat grain natural transverse sections of 12 periods were observed and analyzed using scanning electron micrographs technology and Bio-Quant system IV image analyzer in order to detect the developing process of A- an...Wheat grain natural transverse sections of 12 periods were observed and analyzed using scanning electron micrographs technology and Bio-Quant system IV image analyzer in order to detect the developing process of A- and B-type starch granules. In addition, the chemical composition and starch granule-bound proteins (SGPs) of A- and B-type starch granules were tested and analyzed. The results showed that A-type starch granules in wheat began from 3 d post anthesis (DPA) till grain maturing and B-type starch granules occured after 15 DPA till grain maturing. Approximately 98.5% of chemical compositions in both A- and B-type starch granules were amylose and amylopectin, and more than half of which were amylopectin. The amylopectin contents, average chain length, and chain length distribution (degree of polymerization〉 40) of amylopectin in A-type starch granules were significant higher than that of B-type starch granules. SGP-145, SGP-140, and SGP-26 kD were associated with A-type starch formation in wheat grain.展开更多
To further research the regulatory network of pyruvate dehydrogenase kinase (designated as TaPDK) in physiological male-sterility (PHYMS) of wheat induced by chemical hybridizing agent (CHA) SQ-1, an anther cDNA...To further research the regulatory network of pyruvate dehydrogenase kinase (designated as TaPDK) in physiological male-sterility (PHYMS) of wheat induced by chemical hybridizing agent (CHA) SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium (SD/-Ade/-His/-Leu/-Trp) (QDO), and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor (TanLTP), polyubiquitin (TaPUbi), glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen (TaPCNA), CBS domain containing protein (TaCBS), actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity.展开更多
基金Supported by the Research Projects(CARS-03,BE2013439,CX132021)
文摘In order to obtain genetic information for grain yield, seven genetically diverse wheat cultivars were crossed in an incomplete diallel to study the inheritance of grain yield using F_2 progenies for two years. Significant differences were observed among genotype, year and genotype × year interaction for grain yield, and both general combining ability(GCA) and specific combining ability(SCA) were also highly significant for grain yield, suggesting that the trait was controlled by both additive and non-additive effect. The GCA estimates revealed that the best combiners for grain yield were Yangmai 5 and Ningmai 9. Adequacy tests revealed that data of grain yield was fully adequate for genetic interpretation. Over-dominance genetic effects were important for the expression of grain yield. Grain yield exhibited moderately high value of narrow sense heritability(h_N^2=66.98% and h_N^2=72.37%).
基金Supported by the Program of Beijing Basic Research and Innovation Platform for Agricultural Breeding Ⅱ(No.D080705006900801)National"863"Program(No.2009AA101102,2006AA100102)Beijing Natural Science Foundation(No.5091001)~~
文摘[Objective]The study aimed to map QTLs(Quantitative trait loci)of heading stage for phtopeiod-thermo sensitive male sterile line BS366 in wheat.[Method] A population of 234 doubled haploid derived from the cross between BS366 and Baiyu149 was planted in Beijing and Funan in 2007,respectively.We used composite interval mapping(CIM)method to analyse the QTLs for heading stage.[Result]We detected 15 QTLs for heading stage.8 QTLs were detected in both Beijing and Funan,which were located on 1B,2A,2D,3B(2 loci),6B(2 loci)and 7B.A single QTL accounted for 2.42%-10.98% of pheotypic varience.[Conclusion] Eight QTLs which were detected under two environments could be applied for marker-assisted breeding and improvement of BS366.The QTL on chromosome 1B was new for heading stage,which enriches the QTL resource.
基金Supported by the National Basic Research Program of China(2009CB118602)Young Backbone Teachers Program of Henan Province(2011)~~
文摘[Objective] The aim of this study was to determine the variation of phytic acid content (PAC) and its frequency distribution, as well as the relationship between PAC and protein content, kernel characteristics in 161 Chinese winter wheat cultivars from four regions. [Method] One hundred and sixty-one winter wheat varieties from China Wheat Zones I, II, III and IV (Table 1) were grown in a randomized block de- sign, in the 2009-2011 cropping season; and then the indexes for describing the grain morphological characteristics such as the thousand kernel weight (TKW), kernel length (KL), kernel width (KW) and kernel thickness (KT) were measured; the phytic acid content (PAC), protein content and sedimentation value were also determined; finally, the relationship between PAC and protein content, kernel characteristics were analyzed. [Result] The PAC in the cultivars tested ranged from 0.92% to 1.95% with a mean value of 1.41%. Protein content ranged from 12.60% to 19.20%, with a mean of 15.24%. Most (53.4%) of the wheat genotypes had a PAC value in the range of 1.25% to 1.55%. No significant correlation was found between PAC and protein content, sedimentation value, while protein content and SDS sedimentation value was significant correlated, which suggested the possibility of breeding wheat cultivars that have a low PAC but a high protein content and good gluten quality. There was a high correlation between TKW and KW (,.=0.79), KL (r=0.50) and KT (r=0.64). PAC was found having no significant correlation with TKW, KW, KL and KT. [Conclusion] The result suggests the possibility of breeding wheat cultivars that have a low PAC but high kernel weight.
基金This work was supported by the National Natural Science Foundation of China(No.30471082)the Hi-Tech Research and Development(863)Program of China(No.2006AA100101 and 2006AA10Z1E9).
文摘Quantitative trait loci (QTLs) for plant height in wheat (Triticum aestivum L.) were studied using a set of 168 doubled haploid (DH) lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage map was constructed using 283 SSR and 22 EST-SSR markers. The DH population and the parents were evaluated for wheat plant height in 2005 and 2006 in Tai'an and 2006 in Suzhou. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. Four additive QTLs and five pairs of epistatic effects were detected, which were distributed on chromosomes 3A, 4B, 4D, 5A, 6A, 7B, and 7D. Among them, three additive QTLs and three pairs of epistatic QTLs showed QTL×environment interactions (QEs). Two major QTLs, Qph4B and Qph4D, which accounted for 14.51% and 20.22% of the phenotypic variation, were located similar to the reported locations of the dwarfing genes Rhtl and Rht2, respectively. The Qph3A-2 with additive effect was not reported in previous linkage mapping studies. The total QTL effects detected for the plant height explained 85.04% of the phenotypic variation, with additive effects 46.07%, epistatic effects 19.89%, and QEs 19.09%. The results showed that both additive effects and epistatic effects were important genetic bases of wheat plant height, which were subjected to environmental modifications, and caused dramatic changes in phenotypic effects. The information obtained in this study will be useful for manipulating the QTLs for wheat plant height by molecular marker-assisted selection (MAS).
文摘The effects of osmotic stress on the ATPase activity, the contents of —SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [Triticum aestivum L. cv. Yumai No.18(drought-tolerant) and cv. Yumai No.9(drought-sensitive)] roots were investigated. The results showed that ATPase activity and —SH group content decreased with polyethylene glycol(PEG) 6000(-0.55 MPa) treatment for 7 d, in concert with the decrease of the ratio of noncovalently conjugated spermidine(NCC-Spd)/noncovalently conjugated putrescine(NCC-Put) and increase of the covalently conjugated putrescine(CC-Put). Osmotic stress injury to Yangmai No.9 seedlings was alleviated greatly with 1 mmol/L exogenous spermidine(Spd), in concert with marked increases of the ratio of NCC-Spd/NCC-Put, —SH group contents and ATPase activity in mitochondrial membrane. Under osmotic stress, the concomitant treatment of Yumai No.18 seedlings with methylglyoxyl bis(guanylhydrazone) (MGBG), an inhibitor of S-adenosyl methionine decarboxylase(SAMDC), and phenanthrolin (o-Phen), an inhibitor of transglutaminase(TGase), caused a significant decrease of the ratio of NCC-Spd / NCC-Put, CC-Put contents, respectively, in concert with the marked decreases of ATPase activity, —SH group content and its tolerance to osmotic stress. All the results above suggested that osmotic stress tolerance of wheat seedlings was associated with the ATPase activity, the contents of —SH group, NCC-Spd and CC-Put in mitochondrial membrane.
文摘Drought is a major constraint in many wheat( Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in a double haploid (DH) population derived from the cross, Hanxuan10×Lumai14, using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Interval mapping analysis revealed that QTLs for drought tolerance at germination stage were located on chromosomes 1B, 2B, 5A, 6B, 7A and 7B, respectively, and the most effective QTL was mapped on chromosome 2B, explaining 27.2% of phenotypic variance. The QTLs for drought tolerance at seedling stage were located on 1B, 3B and 7B, respectively, and the most effective QTL was mapped on chromosome 3B, explaining 21.6% of phenotypic variance. Their positions were different from those of QTLs conferring drought tolerance at germination stage, indicating that drought tolerance at germination stage and seedling stage was controlled by different loci. Most of the identified QTLs explained 18% or more of phenotypic variance for drought tolerance at germination and seedling stage, and would be useful in future for marker assisted selection programs and cultivar improvement.
基金supported by the National Natural Science Foundation of China (31271661, 30871477)the National Basic Program of China (2009CB118602)the Special Fund for Agro-Scientific Research in the Public Interest of China (201203100)
文摘Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and the functionality of wheat products. Two high-yield winter wheat cultivars were used to evaluate the effects of the application of exogenous ABA or GA during the reproductive phase of the initial grain filling on starch granule size distribution and starch components in grains at maturity. The results indicated that a bimodal curve was found in the volume and surface area distribution of grain starch granules, and a unimodal curve was observed for the number distribution under all treatments. The exogenous ABA resulted in a significant increase in the proportions (both by volume and by surface area) of B-type (〈9.9 Ixm in diameter) starch granules, with a reduction in those of A-type (〉9.9 ~tm) starch granules, while, the exogenous GA3 led to converse effects on size distribution of those starch granules. The exogenous ABA also increased starch, amylose and amylopectin contents at maturity but significantly reduced the ratio of amylose to amylopectin. Application of GA3 significantly reduced starch content, amylopectin content but increased the ratio of amylose to amylopectin. The ratio of amylose to amylopectin showed a significant and negative relationship with the volume proportion of granules 〈9.9 μm, but was positively related to the volume proportion of granules 22.8-42.8 μm.
基金supported by the National Key Research and Development Program of China(2017YFD0300906-07)
文摘Wheat leaf rust,caused by Puccinia triticina(Pt),is an important foliar disease that has an important influence on wheat yield.The most economic,safe and effective way to control the disease is growing resistant cultivars.In the present study,a total of 46 wheat landraces and 34 wheat lines with known Lr(leaf rust resistance)genes were inoculated with 16Pt pathotypes for postulating seedling resistance gene(s)in the greenhouse.These cultivars and five wheat differential lines with adult plant resistance(APR)genes(Lr12,Lr22b,Lr34,Lr35 and Lr37)were also evaluated for identification of slow rusting resistance in the field trials in Baoding,Hebei Province of China in the 2014–2015 and 2015–2016 cropping seasons.Furthermore,10 functional molecular markers closely linked to 10 known Lr genes were used to detect all the wheat genotypes.Results showed that most of the landraces were susceptible to most of the Pt pathotypes at seedling stage.Nonetheless,Lr1 was detected only in Hongtangliangmai.The field experimental test of the two environments showed that 38 landraces showed slow rusting resistance.Seven cultivars possessed Lr34 but none of the landraces contained Lr37 and Lr46.Lr genes namely,Lr9,Lr19,Lr24,Lr28,Lr29,Lr47,Lr51 and Lr53 were effective at the whole plant stage.Lr18,Lr36 and Lr45 had lost resistance to part of pathotypes at the seedling stage but showed high resistance at the adult plant stage.Lr34 as a slowing rusting gene showed good resistance in the field.Four race-specific APR genes Lr12,Lr13,Lr35 and Lr37 conferred good resistance in the field experiments.Seven race-specific genes,Lr2b,Lr2c,Lr11,Lr16,Lr26,Lr33 and LrB had lost resistance.The 38 landraces showed slow rusting resistance to wheat leaf rust can be used as resistance resources for wheat resistance breeding in China.
基金the National Key Technologies R&D Program for High-Yielding of Food Crops,China(2006BAD02A09)the Program for Changjiang Scholars and Innovative Research Team in University,Ministry of Education(IRT0635)the Academy Doctoral Subject Scientific Research Foundation,Ministry of Education,China(20060434006)
文摘Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and functionality. Two types of wheat cultivars, the hard and soft wheat cultivars, grown at Tai'an Experimental Station of Shandong Agricultural University, Taian, Shandong, China, were examined in this study. The granule size distribution and amylose contents in wheat grains were studied and compared, and relationships between the properties were identified. A clear bimodal distribution of granule size was shown in all wheat cultivars. Volume distribution of starch granules shows the typical bimodal with peak values in the ranges of 5.6-6.1μm and 20.7-24.9μm, respectively. Also, granule surface area distribution was bimodal with peak values in the ranges of 2.4-3.2μm and 20.7-24.9μm, respectively. Number distribution of granules was a typical population with a peak value in the range of 0.54-1.05μm. Contributions from the granules 〈 2.8μm and 〈 9.9μm to the total volume were in the ranges of 94.2-95.1% and 99.7-99.9% of total number, respectively. Proportions of granules〈2.8μm, 2.8-9.9μm, 9.9-22.8μm, and 22.8-42.8μm were in the ranges of 12.9-14.3%, 28.4-31.1%, 33.5-35.6%, and 19.7-22.7% for hard wheat, and 10.3-13.9%, 26.6-28.1%, 32.7-34.6%, and 24.2-27% for soft wheat. Hard wheat had greater B-type granules ( 〈 9.9μm), and had fewer granules of 22.8-42.8μm than soft wheat. Amylose content was positively related to volume percentage of granules 22.8-42.8μm, and negatively related to volume percentage of granules 2.8-22.8μm.
基金supported by the National Natural Science Foundation of China (31271661)the National Basic Research Program of China (973, 2009CB118602)+1 种基金the Special Fund for Agro-Scientific Research in the Public Interest of China (201203100, 201203029)the National Science and Technology Support Program of China (2012BAD04B05)
文摘The quality or structure of a wheat population is significantly affected by the compositions of tillers. Little has been known about the physiological basis for the differences of productive capacity among tillers. Two winter wheat cultivars, Shannong 15(SN15) and Shannong 8355(SN8355), were used to investigate the differences of productive capacity among tillers and analyze the physiological mechanisms that determine the superior tiller group. Low-position tillers(early initiated tillers) had a higher yield per spike than high-position tillers(late initiated tillers) in both cultivars, which was due to their more grain number per spike, more fertile spikelet per spike, less sterile spikelet per spike and higher grain weight. According to cluster analysis, tillers of SN15 were classified into 2 groups: superior tiller group including main stem(0), the first primary tiller(I) and the second primary tiller(II); and inferior tiller group including the third primary tiller(III) and the first secondary tiller(I-p). Tillers of SN8355 were classified into 3 groups: superior tiller group(0 and I), intermediate tiller group(II and III) and inferior tiller group(I-p). In comparison with other tiller groups, the superior tiller group had higher photosynthetic rate of flag leaves, higher antioxidant enzyme(SOD, POD and CAT) activities and lower levels of lipid peroxidation in leaves, higher grain filling rate in both superior and inferior grains during grain filling, higher single-stem biological yield and larger single-stem economic coefficient. Correlation analysis showed that yield per spike was positively and significantly correlated with the flag leaf photosynthetic rate, grain filling rate, the antioxidant enzyme activities and soluble protein content(except for SN15 at 5 days post-anthesis(DPA)) of flag leaf, the single-stem biological yield, and the single-stem economic coefficient. Remarkable negative correlation was also found between yield per spike and MDA content of flag leaf. These results suggested that superior tiller group had stronger leaf photosynthetic capacity, more predominance in terms of grain filling, slower senescence rate, higher biological yield and larger economic coefficient, and therefore, showed greater productive capacity than other tiller groups.
基金supported by the National Technology R&D Program of China (2013BAD07B07, 2015BAD26B01 and 2018YFD0300701)
文摘Soil management practices affect rhizosphere microorganisms and enzyme activities, which in turn influence soil ecosystem processes. The objective of this study was to explore the effects of different nitrogen application rates on wheat(Triticum aestivum L.) rhizosphere soil microorganisms and enzyme activities, and their temporal variations in relation to soil fertility under supplemental irrigation conditions in a fluvo-aquic region. For this, we established a split-plot experiment for two consecutive years(2014–2015 and 2015–2016) in the field with three levels of soil moisture: water deficit to no irrigation(W1), medium irrigation to(70±5)% of soil relative moisture after jointing stage(W2), and adequate irrigation to(80±5)% of soil relative moisture after jointing stage(W3);and three levels of nitrogen: 0 kg ha^–1(N1), 195 kg ha^–1(N2) and 270 kg ha^–1(N3). Results showed that irrigation and nitrogen application significantly increased rhizosphere microorganisms and enzyme activities. Soil microbiological properties showed different trends in response to N level;the highest values of bacteria, protease, catalase and phosphatase appeared in N2, while the highest levels of actinobacteria, fungi and urease were observed in N3. In addition, these items performed best under medium irrigation(W2) relative to W1 and W3;particularly the maximum microorganism(bacteria, actinobacteria and fungi) amounts appeared at W2, 5.37×10^7 and 6.35×10^7 CFUs g^–1 higher than those at W3 in 2014–2015 and 2015–2016, respectively;and these changes were similar in both growing seasons. Microbe-related parameters fluctuated over time but their seasonality did not hamper the irrigation and fertilization-induced effects. Further, the highest grain yields of 13 309.2 and 12 885.7 kg ha^–1 were both obtained at W2 N2 in 2014–2015 and 2015–2016, respectively. The selected properties, soil microorganisms and enzymes, were significantly correlated with wheat yield and proved to be valuable indicators of soil quality. These results clearly demonstrated that the combined treatment(W2 N2) significantly improved soil microbiological properties, soil fertility and wheat yield on the Huanghuai Plain, China.
基金supported by the National Natural Science Foundation of China (31371618)the Research Plan of Application Base of Hebei, China (17962901D)
文摘Through regulating target genes via the mechanisms of posttranscriptional cleavage or translational repression, plant miRNAs involve diverse biological processes associating with plant growth, development, and abiotic stress responses, in this study, we functionally characterized TaMIR1119, a miRNA family member of wheat (Triticum aestivum), in regulating the drought adaptive response of plants. TaMIR1119 putatively targets six genes categorized into the functional classes of transcriptional regulation, RNA and biochemical metabolism, trafficking, and oxidative stress defense. Upon simulated drought stress, the TaMIR1119 transcripts abundance in roots was drastically altered, showing to be upregulated gradually within a 48-h drought regime andthat the drought-induced transcripts were gradually restored along with a 48-h recovery treatment. In contrast, most miRNA target genes displayed reverse expression patterns to TaMIR1119, exhibiting a downregulated expression pattern upon drought and whose reduced transcripts were re-elevated along with a normal recovery treatment. These expression analysis results indicated that TaMIR1119 responds to drought and regulates the target genes mainly through a cleavage mechanism. Under drought stress, the tobacco lines with TaMIR1119 overexpression behaved improved phenotypes,, showing increased plant biomass, photosynthetic parameters, osmolyte accumulation, and enhanced antioxidant enzyme (AE) activities relative to wild type. Three AE genes, NtFeSOD, NtCAT1;3, and NtSOD2,1, encoding superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) proteins, respectively, showed upregulated expression in TaMIR1119 overexpression lines, suggesting that they are involved in the regulation of AE activities and contribution to the improved cellular reactive oxygen species (ROS) homeostasis in drought-challenged transgenic lines. Our results indicate that TaMIR1119 plays critical roles in regulating plant drought tolerance through transcriptionally regulating the target genes that modulate osmolyte accumulation, photosynthetic function, and improve cellular ROS homeostasis of plants.
基金supported by the Natural Science Foundation of Shandong Province,China(ZR2009DQ009)the National Natural Science Foundation of China(30971764 and 31171554)the National Major Projects of Cultivated Transgenic New Varieties Foundation of China(2011ZX08002-003 and 2009ZX08002-017B)
文摘To evaluate the possible genetic interrelationships between flour components and the sedimentation volume(SD),a doubled haploid(DH) population comprising 168 lines were used to identify the conditional quantitative trait loci(QTLs) for SD in three environments.Ten additive QTLs and 15 pairs of epistatic QTLs were detected for SD through unconditional and conditional QTL mapping.Three major additive QTLs were detected for SD conditioned on the seven quality traits.Two additive QTLs were found to be independent of these traits.Three additive QTLs were suppressed by three of the seven traits because of non-detection in unconditional mapping.Three pairs of epistatic QTLs were completely affected by the seven traits because of detection in unconditional mapping but no-detection in conditional mapping.Twelve pairs of epistatic QTLs were detected in conditional mapping.Our results indicated that conditional mapping could contribute to a better understanding of the interdependence of different and closely correlated traits at the QTL molecular level,especially some minor QTLs were found.The conditional mapping approach provides new insights that will make it possible to avoid the disadvantages of different traits by breeding through molecular design.
基金financially supported by a grant from Tarbiat Modares University,Tehran,Iran
文摘The relationship between vernalization requirement and quantitative and qualitative changes in total leaf soluble proteins were determined in one spring (cv. Kohdasht) and two winter (cvs. Sardari and Norstar) cultivars of wheat (Triticum aestivum L.) exposed to 4℃. Plants were sampled on days 2, 14, 21 and 35 of exposure to 4℃. The final leaf number (FLN) was determined throughout the vernalization periods (0, 7, 14, 24, and 35 d) at 4℃. The final leaf number decreased until days 24 and 35 in Sardari and Norstar eultivars, respectively, indicating the vernalization saturation at these times. No clear changes were detected in the final leaf number of Kohdash cultivar, verifying no vernalization requirement for this spring wheat cultivar. Comparing with control, clear cold-induced 2-fold increases in proteins quantity occurred after 48 h following the 4℃-treatment in the leaves of the both winter wheat cultivars but, such response was not detected in the spring cultivar. However, the electrophoretic protein patterns showed between-cultivar and between-temperature treatment differences. With increasing exposure time to 4℃, the winter cultivars tended to produce more HMW polypeptides than the spring cultivar. Similar proteins were induced in both Sardari and Norstar winter wheat cultivars, however, the long vernalization requirement in Norstar resulted in high level and longer duration of expression of cold-induced proteins compared to Sardari with a short vernalization requirement. These observations indicate that vernalization response regulates the expression of low temperature (LT) tolerance proteins and determines the duration of expression of LT- induced proteins.
基金supported by the Chinese National Programs of Science and Technology for High Yielding Crop Production (2011BAD16B08, 2012BAD04B06, and 2013BAD07B05)the Key Laboratory of Crop Growth Regulation of Hebei Province, China
文摘In this study, 14 wheat cultivars with contrasting yield and N use efficiency (NUE) were used to investigate the agronomic and NUE-related traits, and the N assimilation-associated enzyme activities under low and high N conditions. Under deficient-N, the cultivars with high N uptake efficiency (UpE) and high N utilization efficiency (UtE) exhibited higher plant biomass, yields, and N contents than those with medium and low NUEs. The high UpE cultivars accumulated more N than other NUE type cultivars. Under sufficient-N, the tested cultivars showed similar patterns in biomass, yield, and N content to those under deficient-N, but the varietal variations in above traits were smaller. In addition, the high UpE cultivars displayed much more of root biomass and larger of root length, surface area, and volume than other NUE type cultivars, indicating that the root morphological traits under N deprivation are closely associated with the plant biomass through its improvement of the N acquisition. The high UtE cultivars showed higher activities of nitrate reductase (NR), nitrite reductase (NIR), and gluta- mine synthetase (GS) at stages of seediling, heading and filling than other NUE type cultivars under both low and high N conditions. Moreover, the high UpE and UtE cultivars also displayed higher photosynthetic rate under deficient-N than the medium and low NUE cultivars. Together, our results indicated that the tested wheat cultivars possess dramatically genetic variations in biomass, yield, and NUE. The root morphological traits and the N assimilation enzymatic acitivities play critical roles in regulating N accumulation and internal N translocation under the N-starvation stress, respectively. They can be used as morphological and biochemical references for evaluation of UpE and UtE in wheat.
文摘Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yandal817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157, Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.
基金supported by the National Natural Science Foundation of China (30860145)
文摘Wheat grain natural transverse sections of 12 periods were observed and analyzed using scanning electron micrographs technology and Bio-Quant system IV image analyzer in order to detect the developing process of A- and B-type starch granules. In addition, the chemical composition and starch granule-bound proteins (SGPs) of A- and B-type starch granules were tested and analyzed. The results showed that A-type starch granules in wheat began from 3 d post anthesis (DPA) till grain maturing and B-type starch granules occured after 15 DPA till grain maturing. Approximately 98.5% of chemical compositions in both A- and B-type starch granules were amylose and amylopectin, and more than half of which were amylopectin. The amylopectin contents, average chain length, and chain length distribution (degree of polymerization〉 40) of amylopectin in A-type starch granules were significant higher than that of B-type starch granules. SGP-145, SGP-140, and SGP-26 kD were associated with A-type starch formation in wheat grain.
基金supported by the National High-Tech R&D Program of China(2011AA10A106)the National Natural Science Foundation of China(31071477,31171611)the Key Scientific and Technological Innovation Special Projects of Shaanxi"13115",China(2010ZDKG-68,2011KTZB02-01-01)
文摘To further research the regulatory network of pyruvate dehydrogenase kinase (designated as TaPDK) in physiological male-sterility (PHYMS) of wheat induced by chemical hybridizing agent (CHA) SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium (SD/-Ade/-His/-Leu/-Trp) (QDO), and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor (TanLTP), polyubiquitin (TaPUbi), glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen (TaPCNA), CBS domain containing protein (TaCBS), actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity.